Treating White Fungus or Mealybugs on Large Cacti

Treating White Fungus or Mealybugs on Large Cacti

A reader has 6-foot-tall cacti with white fungus, owned for years, wants to save them.

Identification First

• Fungus: Hard, crusty appearance.
• Mealybugs: Soft, cotton-like texture.

Send a photo if unsure.

Treatments

• Fungus: Sulphur-based fungicide spray (reasonably safe).
• Mealybugs: Spray mix of 6 parts water, 1 part rubbing alcohol, plus a squirt of liquid soap.

Apply thoroughly; repeat as needed.